23 Jan
2017
23 Jan
'17
10:06 p.m.
On Mon, Jan 23, 2017 at 11:38 PM, Adrian Graham
<witchy at binarydinosaurs.co.uk> wrote:
Are you telling me that if you put 2 logic analyser inputs on 2 points on the
same trace (which tests as continuous with an ohmmeter) that said 2 LA
channels don't show the same thing? If so, the LA needs repairing!
Given the problems I've had with even clean old sockets, I would have
replaced those. Corroded sockets must be worse. And I can't believe
they used turned-pin sockets in something like this.
-tony
On 23/01/2017 21:38, "Tony Duell"
<ard.p850ug1 at gmail.com> wrote:
Oh... The
trace isn't open-circuit, is it? Check it with the
multimeter. Given the
corrosion damage to the tape drive I could well believe PCB problems of a
similar nature.
I've measured resistance from all points to all points, there's 9:
74LS373 (output, new socket checked for solder bridges, new chip)
4x 2764 EPROM (new chips, no new sockets yet)
MC3242A (new chip, no new socket yet, this one had bad verdigris)
74LS139
74LS21
74LS365
and it's 0.6ohm max.